Severe fps lag issues

I have recently discovered upon playing on the ttt server that there are problems with missing textures.
The console is filled with an incredible amount of errors that it causes severe fps lag and others have reported this happening too.

I was wondering if anyone else has problems with this and also if others more experienced with these things go check it out?

EDIT: Apparently the errors disappeared later on but I'm guessing this was something to do with downloaded/workshop content perhaps